# addToolTip(_:owner:userData:) Creates a tooltip for a defined area in the view and returns a tag that identifies the tooltip rectangle. ``` func addToolTip(_ rect: NSRect, owner: Any, userData data: UnsafeMutableRawPointer?) -> NSView.ToolTipTag ``` ## Parameters `rect` A rectangle defining the region of the view to associate the tooltip with. `owner` An object from which to obtain the tooltip string. The object should either implement , or return a suitable string from its method. It can therefore simply be an object. > Important: > The view maintains a weak reference to `owner`. You’re responsible for ensuring that `owner` remains valid for as long as it may be needed. `data` Any additional information you want to pass to ; it isn’t used if `owner` doesn’t implement this method. ## Return Value An integer tag identifying the tooltip; you can use this tag to remove the tooltip. ## Discussion The tooltip string is obtained dynamically from `owner` by invoking either the `NSToolTipOwner` informal protocol method , if implemented, or the protocol method . --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)